| Title | Thermal Surveying of Mahallat Geothermal Prospect in Central Iran and Comparing Its Results to the Mödruvellir Geothermal Field, SW Iceland |
|---|---|
| Authors | Davar EBRAHIMI, Javad NOURALIEE, Ali DASHTI |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Thermal Surveying, Geothermal Prospect, Mahallat, Mödruvellir, Iran, Iceland |
| Abstract | In the present study, thermal surveying of a low temperature geothermal field which is located in the central parts of Iran (close to Mahallat City) has been carried out. Seven exploration boreholes with different depths (between 30 to 110 m) have been drilled to detect the subsurface characteristics of this area. Thermal maps of the area are prepared using the geothermal gradient method to detect location of the thermal anomaly. The Mödruvellir geothermal prospect is located in the SW of Iceland and falls into low temperature geothermal resource category. Thermal surveying of this region have been carried out by the author in 2015. This study is conducted based on the data collected from 22 gradient boreholes, and also existing two geothermal wells. Thermal maps are provided for the depths horizon of 50 meters in both regions and their geothermal gradients are calculated. In the case of Mödruvellir, 5 thermal zones are detected with thermal gradients ranging from 160 to 300 °C/km. In Mahallat geothermal region, 3 zones are detected and the geothermal gradient is estimated to be ranging from 71 to 108 °C/km. Comparison of these regions revealed that the thermal zones of Mödruvellir region has a higher temperature than the Iranian Mahallat prospect. Geothermal gradient of Mödruvellir is also higher than Mahallat region. Distinguished thermal anomalies of Mahallat prospect are known to be in close relation with the activity of large thrust faults that paved the way for circulation of water through fractures. In the case of Mödruvellir region, it is confirmed that the geothermal reservoir is associated with a graben structure sandwiched between two main normal faults. |